This project is directed towards understanding the life cycle of the human retroviruses, especially human immunodeficiency virus type 1 (HIV-1). Studies are currently focused on the following areas: 1) developing antiviral treatments based on anti sense and gene therapy approaches, with emphasis on targeting the viral regulatory genes, especially tat and rev; 2) the development of delivery systems for the introduction of antiviral genes; 3) characterization of the role of DNA contained in virus particles, especially with respect to its role in infection of nondividing cells; 4) correlation of proviral integration state with viral gene expression; and 5) studies on how different genotypes of HIV-1 interact to confer new biological properties.